As pointed out by the Zend Developer Zone today, there's a useful forum post over on the YoungCoders.com website that talks about very useful feature that some PHP developers just don't use - ticks.

You've probably never used it, never saw it, or never found a practical use for ticks, a underused and powerful feature of PHP that allows you to implement exceptions in PHP4, do intensive debugging and profiling, check database connections, turn PHP into an event driven language, or harness complex control over your code.

The post talks about what ticks are, how to enable them, and a few examples of how to use them. Check out more about them in this page on the PHP Manual.